Self-erecting box with locking bottom



Feb. 15, 1955. D. A. LINSON 2,

SELF-ERECTING BOX WITH LOCKING BOTTOM Filed May 22, 1952 2 Sheets-Sheet l INVENTOR. DON A. LINSON 3 a d. 0AM

Feb. 15, 1955 D. A. LINSON SELF-ERECTING BOX WITH LOCKING BOTTOM 2 Sheets-Sheet Filed May 22, 1952 INVENTOR. DON A. Ll NSON 'ifl. W /4 FIG. l2

SELF-EREC'IING 30X WITH LOE'JKING BOTTOM Don A. Linson, Indianapolis, Ind assiwor to Paper Package Company, Indianapolis, Ind., a corporation of Indiana Application May 22, 1952, Seriai No. 289,258

3 Claims. (Cl. 229-39) This invention relates to boxes and more particularly to boxes of the foldable, self-erecting type.

Boxes for merchandising small fruits such as cherries, berries and like produce have heretofore, customarily been made of thin, wood slat stock, with fairly substantial, solid bottoms. The habits of the trade in examining such produce prior to purchase has been to place the fingers beneath the bottom of the box and, with the thumb resting on its upper edge, to lift the box into inspection range. These wooden boxes frequently splinter; they also have the disadvantage of using wire staples in their construction, the splinters and staples tending to catch on and bruise the fruit or cause injury to the consumer. it has been desirable for these reasons as well as for reasons of economy, appearance and to enable facile printing thereon for. advertising purposes to provide boxes made of paper stock or cardboard for merchandising produce. in the main, however, the efiicient, self-erecting type of cardboard box such as would be ideally suited for this purpose since it is economical to produce and free of staples, has had an objectionable drawback in that the infolding-outfolding bottoms thereof lack sufiicient rigidity tow'ithstand the upward pressure of the fingers. Such boxes have been designed primarily to contain and sustain relatively heavy mer chandise such as base balls, jars of cosmetics and the like from falling downwardly and out of the boxes, the weight of such articles being relied upon to maintain the bottoms outfolded and generally sulficient to prevent any untoward inward and upward displacement of the bottoms. With relatively lightweight produce such as mentioned above, however, and with the ingrained habit of uplifting such boxes for inspection as heretofore mentioned, it is vitally necessary that the bottoms of paperboard boxes have substantially the same strength characteristics as the previously mentioned wooden boxes.

Accordingly, it is an object of the present invention to provide a box of the foldable, self-erecting cardboard type having a bottom that is sufliciently rigid and positively locked in open form to insure against any tendency toward inward displacement when lifted with the fingers resting thereunder.

It is a further object of theinvention to provide a box of this character which is simple in design and construction, is economical to manufacture in large quantities and is especially useful in merchandising berries and similar produce.

It is a feature of theinvention to provide in a box of this character a construction wherein certain locking lugs which are utilized in securing the bottom in locked 1 position are protected against deformation or distortion when the box is in unopened or unfolded condition, so that such lugs will remain flat, unbent and rigid ready to effect a secure locking engagement when the box is opened into containing position.

With these and other features and objects in view the invention consists in the construction, arrangement and combination of the various parts, whereby the objects contemplated are obtained as hereinafter more fully set forth, pointed out in the claims and illustrated in the accompanying drawings, wherein:

2,102,154 Patented Feb. 15, 1955 Fig. 1 is perspective view of one form of box constructed according to the invention, said box being shown in open position,

Fi 2 is a plan view of the single-piece blank from which this form of box is constructed,

Fig. 3 is a side elevation of the assembled box in collapsed or folded position, certain parts being broken away for clearness,

Fig. 4 is a view similar to Fig. 3 but with more of the parts being broken away for further clearness,

Fig. 5 is a sectional elevation taken along the line 55 of Fig. 4,

Fig. 6 is a top plan view of such box in erected position,

Fig. 7 is a bottom plan view of the same,

Fig. 8 is a perspective view of a modified form of box embodying the invention, the box being shown in open position,

Fig. 9 is a plan view of the one-piece blank used in constructing such modified form,

Figs. 10 and 11 are side elevations of such modified form in collapsed position, certain parts being broken away for clearness,

Fig. 12 is a sectional elevation taken along the line 12-12 of Fig. 11,

Fig. 13 is a top plan view of the modified form of box in erected position, and

Fig. 14 is a bottom plan view of the same.

The invention is shown in Figs. 1 and 8, and will hereinafter be described, as applied to boxes having sloping sidewalls, i. e., boxes following the same general form as the conventional, wooden, berry boxes presently being used. While such sloping sidewall construction forms a feature of the invention in that provision is thereby made to protect certain of the locking lugs against being deformed, as will be hereinafter more fully explained, the invention is applicable to straight or non-sloping side wall boxes but with possible sacrifice of such protective feature with respect to all of such locking lugs as may be employed in the straight sidewall construction.

Referring now to Figs. 1 and 2, the box is formed of a single'piece of cardboard stock divided into continuous sidewalls 20, 21, 22 and 23 integrally hinged together by upright, angularly disposed, hinge-crease score lines 24. A flap 25 formed integrally with the outer free end of sidewall 23 is adapted to be glued or otherwise fastened to the outer free end of sidewall 20 at that area designated by dotted lines at 26 in Fig. 2.

Each of the sidewalls 20, 21, 22 and 23 is provided with a corresponding, dependingly hinged bottom-forming flap 27, 28, 29, and 30, the hinges'for said flaps being provided by transverse, hinge-crease score lines 31. Flaps 27 and 29 are each formed with a hingedly appended tab 32 and 33, respectively, the tabs being adapted to be backfolded against their associated flaps upon diagonally disposed perforate or weakening lines 34. The upper surfaces of tabs 32 and 33 are glued or otherwise suitably affixed to the undersurfaces of flaps 28 and 30, respectively, at the areas indicated in dotted lines at 35 in Fig. 2. With tabs 32 and 33 thus afiixed to flaps 28 and 30 and with flaps 25 secured to the area 26 of sidewall 20 the box is folded fiat as shown in Figs. 3 and 4 into collapsed position. In such position sidewalls 21 and 22 are in matched, paired confronting relation with sidewalls 20 and 23, bottom forming flaps 27, 28, 29, and 30 are cooperatively infolded upon the hinge-crease score lines 31 and tabs 32 and 33 cooperatively backfolded on their perforate or weakening hinge lines 34 as clearly shown in Figs. 4 and 5.

To erect the box it is merely necessary to apply in ward pressure as suggested by the arrows in Fig. 3, against the two, oppositely disposed, outer edges formed by the hinge-crease score lines 24. This causes the paired sidewalls 20-21 and 22-23 to move outwardly away from each other and, simultaneously causes the interafiixed, companion, bottom-forming flaps and tabs cal of boxes known in the art as of the self-erecting type.

As previously stated, while this type of box generally provides a bottom that is sufficiently resistant to displacement from the horizontal, downwardly by pressure from within, such bottoms are usually readily displaceable upwardly by pressure (especially against their central portions) from without. This easy, upward yielding of the bottoms renders such boxes unsuitable for containing relatively lightweight contents such as berries or similar produce which, as before stated, are more or less routinely inspected by raising the boxes containing them with the fingers bearing upwardly against their bottoms.

To overcome this objectionable easy upward yielding characteristic, certain of the bottom-forming flaps, more particularly in this instance, flaps 28 and 30 are formed of such dimensions that certain of their free edges 36, 37, 38 and 39 meet substantially flush with the sidewallbottom flap hinge corners 31 upon erection of the box as shown in Figs. 1 and 6.

A pair of oppositely disposed, outwardly projecting locking lugs 40 and 41 are each formed integrally with flap 28 in spaced relation along the edges 36 and 37, respectively, adjacent the innermost free edge 42 of said flap. Slots 43 and 44 of a width corresponding to the width of lugs 40 and 41 and of a height corresponding to the thickness of the cardboard stock are struck from sidewalls 20 and 22 in complementary spaced relation along their transverse hinge-crease score lines 31 which form the complementary hinge corners that are met by edges 36 and 37 upon erection of the box into open form. Consequently, upon erection of the box, as bottom flap 28 is pulled downwardly, lugs 40 and 41 move downwardly therewith past the upper edges of their corresponding slots 43 and 44, and snap into home or locking position withinthe slots. This lug-slot engagement, coupled with the substantially flush meeting of edges 36. 37, 38 and 39 provides a lock for the bottom that positively prevents its displacement either upwardly or downwardly from the horizontal and thus materially rigidifies and strengthens the general box structure.

It is seen that the lock thus provided becomes effective at the periphery of the bottom immediately beneath the stiff, erect and rigid sidewalls and is not dependent upon weakened interlocking tongues interengaging at or near the central or normally the weakest portion of the bottom. Moreover, the lock thus provided utilizes only stock that would, for the form and dimensions of the box illustrated, otherwise be waste or scrap, i. e., there is no waste of material in providing the locking construction such as there is where foldover, partial double sidewalls or endwall construction is used.

It is noted that when the box is in the folded form as shown in Fig. 3, the angle of the slope of the sidewalls 20 and 21 accommodates with clearance the locking lug 40 so that both of the locking lugs 40 and 41 remain flat and undeformed in outward projecting position ready for sturdy locking engagement within their complementary slots 43 and 44 upon erection of the box. The provision of this clearance recess by the angularity of the sloping sidewalls provides an important feature of the invention in that it insures maintenance of initial stability and rigidity to the locking lug 40 when and while the box is folded as shown in Figs. 3 and 4, such stability being a material factor in securing a sturdy locking action.

It will be understood of course, that if desired, more than one locking lug may be provided along the edges 36 md 37. It has been foundin practice, however, that the air of lugs as just described and shown in Fi s. 1. 2, and i provide a very substantial bottom lock. The form of .to): iust described and as exemplified in its blank form in =ig. 2 is extremely econ mical in the blanking-out process 'or, as will be observed from reference to that figure, there s no substantial sin le portion of the box extendin bevond the confines of the outer delineation of the blank. This materiallv conserves the use of st ck and eliminates wa e of board between successive multiple blanks in the di ng out pro ess.

In the modified form of the box shown in Fi s. 8-14, inclusive. the same reference numerals with exponents are applied to parts that are identical to the parts already described. In this modified form, the bottom-forming flap 45 (Figs. 8 and 9) is formed so that each of its three free edges 46, 47, and 48 meet substantially flush with the hmge corners formed by the junction of sidewalls 22' and 23' and bottom-forming flaps 27', 29', and 30, along the transverse, hinge-crease score lines 31. Outwardly projecting locking lugs 49, 50, and 51 are formed integrally with flap 45 in spaced relation along the edges 46, 47, and 48, respectively, and corresponding lug-receiving slots 52, 53 and 54 are provided in spaced relation adjacent to the hinge-crease score lines 31' in sidewalls 20', 22' and 23' to receive and lock the lugs when the box is in erected, open form as shown in Figs. 8, 13 and 14. The provision of the three locking lugs provides a lock having superior strength against displacement of the bottom from the horizontal over the form of box first described and shown in Figs. 1 to 7, inclusive. However, the modified form of box just described is not as economical to manufacture because the increased length of bottom flap 45 results in certain waste of material between the multiple forms in the blanking out process.

. In use, however, both forms of the box as described in the foregoing have proven very efiicient and satisfactory. Their bottom locks are more than adequate to withstand upward stress of fingers applied against their bot toms. They provide a simple, inexpensive and reliable container for merchandising produce and the like. No especial machinery is required for the manufacture and assembly of the boxes and all of the objectionable features heretofore mentioned with respect to the use of staples, splintering and untoward upward displacement of bottoms are obviated.

I claim:

1. A box of the class described; comprising a single blank having four, hinged-together, continuous, sloping sidewalls; each sidewall having a bottom-forming flap hingedly depending therefrom; said sidewalls having lugreceiving slots spaced along and adjacent to said bottomflap-sidewall hinged connections; one alternate pair of said flaps being substantially coterminous with the width of said box bottom and being imperforate, uncreased and unweakened throughout their surface areas; the other alternate pair of said flaps each having a weakening line extending angularly across its surface area defining a tab foldable along said line; each of said tabs being affixed in opposed bias relation to the undersurface of that one of said unweakened flaps lying respectively next adjacent thereto whereby upon said box being collapsed, all of said flaps are cooperatively and positively pushed upwardly within said sidewalls and, conversely, upon said box being opened all of said flaps are cooperatively and positively pulled downwardly into bottom-forming relation; said unweakened flaps being of such relative lengths that one overlies at least a portion of the other and combinedly both completely overlie and reinforce the tabdefining fold lines of said weakened flaps when said box is in erected position; the uppermost of said unweakened flaps having spaced lugs projecting peripherally'there from adapted to engage within said lug-receiving slots to thus lock said lug-carrying flap and the associated subjacent, bottom-forming flaps positively against displacement.

2. A box of the single blank, prefolded, self-erecting type including four hinged-together, continuous sidewalls formed to slope and each having dependingly hinged bottom-forming flaps and tabs formed on one alternate 'pair of said flaps adapted to be cooperatively affixed to the other alternate pair of said flaps whereby said flaps and tabs infold and backfold on hinge-crease-score lines and perforate lines, respectively, when the box is in folded, closed form and cooperatively outfold on said lines into bottom-forming position upon erection of said box to open form; all of the free edges of at least one of said other alternate pair of flaps meeting substantially flush with the sidewall-bottom flap hinge corners upon said erection; at least one outwardly projecting lug formed in spaced relation along and integrally with each of said free edges; and complementary lug-receiving slots provided in correspondingly spaced relation along the complementary hinge-corners met by said lug-carrying edges, whereby upon erection of said box into open form said lugs are received and engaged by their respective complementary slots to lock said one of said bottom-forming and its associated bottom-forming flaps positively against displacement, and thus materially rigidify and strengthen the general box structure.

References Cited in the file ofthis patent UNITED STATES PATENTS Sutherland Ian. 2, 1934 Gruber et al Ian. 11, 1938 Powell Sept. 11, 1945 Phillips Sept. 25, 1951 

